Pneumatic tool.



IVI'. W. SHEHWOOD.

19W. 2 SHEETS-SHEET I.

Paten Oct, 23,

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' IvI. w. sHERwoon PNEUMATIC TOOL.

APPLICATION FILED FEB. 24, |914.

1,243,770. Patented Oef. 23, 1917.

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MATHEN W. sHEnWOOD, OF FRANKLIN, PENNSYLVANIA, AssIGNoR To CHICAGO INLUMAEIIO TOOL COMPANY, oF CHICAGO, ILLINOIS, A OORPOB r'rIoN OF NEW JERSEY,

PNEUMATIC TOOL.

Specification of `Letters Patent. Patented 0013.23, 1.

Application filed February 24, 1914. serial/Nt. 820,548.

To all whom t may concern:

Be it known that I, MATHER W. SHER-f woon, a' citizen of the United States, residing at Franklin, inthe county of lVenango and State of Pennsylvania, have invented certain neW- and useful Improvements in Pneumatic Tools, vof which lthe following is a specification.

My invention relates to tools `'operated by a motive fluid, usually compressed air and therefore commonly called pneumatic tools. The object of my invention is to provide 'a simple and eflicient construction of tool embodying means for rotating the working tool through the medium of the motive yfluid employed in the operation of the tool. Inthe present instance my invention is embodied in a type of pneumatic tool known as a hand drill employed more particularly as a rock 'drill and the working tooll is consequently a drill bit which is positively operated during the drilling operation by the' motive fluid. y n

In the drawings, Figure lis a central longitudinal section of a hand4 drillembodying my invention but showing the handle mostly in elevation; Figs. 2, 3 and el are sections on the lines 2--2, 3 3 and of Fig. 1; Fig. 5 an elevation of one of the ratchet rings; Fig. 6 an edge View thereof; Fig. 7 an elevation of the, locking ratchet ring;

Fig. 8 an edge view thereof, Fig. 9 an elevation of the inner end of the drill chuck, and Fig. 10 a section on the line 10-10 of Fig. 1. 4

For thev purposes of a clear and definite description of my invention I have shown the same embodied in a type of drill known as a hand drill vbut it will be `umlerstood that my invention is not to be limited thereto and thatI contemplate using the same wher-v ever applicable.

Referring to the particular embodiment 0f my invention as herein shown the drill comprises a main cylinder 1 having a piston chamber 2, a piston 3 reciprocable therein and having a hammering portion or stem 3, a striking piece or anvil el, a drill bit 5, a front head 6. a rotatable drill chuck -or socket 7 anda suitable handle .8 secured to the cylinder b v the side rods 9 which also serve to clamp and hold the front head. T he piston chamber 2 has comniunication with the live motive fluid entering through the inlet connection 10 through'snitable ports -the other cylinder;

and passages governed by a distributing valve which is here in the form of a b all 11. The piston ychamber'is also in communication with the atmosphere through suitable ports and passages, 'all of which ports and *passages will be hereinafter more Aparticuopposite slots 7.

lThe Vmeans for positively rotating the chuck are contained within a casingl which is interposed between the front end -of the main cylinder and thefront head 6 and is clamped therebetween b v means of the side rods 9 in the manner clearly indicated in Figa. This casing has a'central portion 12 provided with ai Central bore whose axis is coincident with the axis of the longitudinal axis of the main c vlinderand which accom-v modates the working parts of Ithe mechanism. The casing is alsoprovided at diametrically opposite sides with two similar rotation cylinders 13 and 14. By prirference theentire casing is made in two separable parts-or Sections which are held .together in suitable manner as b v lneans of the bolts 15. NVithin the rotation cylinders 13 and 11 are arranged two pairs of pistons 16 and 1T which are preferably hollow and of rectangular section and also independent of each other except that .they move in unison in the manner hereinafter explained.

For the purpose of reciprocating'. the pistons 16 and'lT by means of the motive tlu'id i of the tool the opposite ends of the rotation cylinders 13 and 1l are connected at theii opposite ends with the opposite endsof the main'piston chamber in such manner` that when the lmotive fluid is admitted to one end of'a cylinder the motive tluid will be simultaneously admitted to the opposite end of ln the present inst-ance the main piston chamber 2 communicates near its rearward end with two similar ports and passages 1S extending longitudinally of the'cylinder and after passing' partiall)r through the easing l2 enter the left-hand end of the rotation cylinder 1li and the right- Iparts are Viewed as in section 2.

. tion shown in Fig. 1 with the ball-valve in its left-hand position, the live motive Huid enters through the connection 10 through the port 20 and passages 21 and 22 into the front end ofthe main piston chamber with the result that the piston 3 is returned to its rearward position. The live motive fluid at the front end of the main piston chamber passes through the ports 19 to the ends of the rotation cylinders 13 and 14driving the pistons 1G and 17 to the opposite ends of said cylinders and operating the chuckdriving mechanism in the manner hereinafter explained. moves to its right-hand position the livel motive fluid is admitted to the rear end oit the main piston chamber with the result that the live motive fluid passes through the ports and passages 18 to the other ends of the rotation cylinders 13 and 14 and drives the pistons 1G and 17 to the `opposite ends of their piston chambers. Then the valve is in said right-hand lposition the live motive fluid enters through the connection 10, through the ports 23 and 24 into the rear end of the main piston chamber.

A vdriven ratchet ring 25 which is shown in detail in Figs, 5 and 6 fits upon the inner edge of the drill chuck, the slots 7a of which receive the opposite similarly-shaped lugs This ratchet ring coperates with a driving ratchet ring 2G, the ratchet teeth of the two rings being adjacent each other in cooperative relationship. This driving ring is provided at diametrically opposite sides with radial operating arms 27 and 28 projecting through the slots `or openings and 30 extending into the two rotation cylinders 13 and 14 respectively. The arm 27 projects into the rotation cylinder 13 and between the two pistons 1G while the other arm 28 projects into the rotation cylinder 14 between the two pistons 17. As the result of this construction and arrangement the pistons 1G and 17 by. their reciprocations cause an oscillating movement of the driving ratchet ring 2G. lVhen this ring is driven in one direction its ratchet teeth will drivingly engage the driven ring 25 which being in engagement with the drill chuck causes a rotation of the latter. When the ratchet ring 26 is moved in the opposite direction its ratchet teeth will ride upon Wheny the ball-valve 11k the teeth of the driven ring and at the end of such movement will obtain a new engagement therewith, ready for the next reciprocation of the pistons 1G and 17. The driving and the driven rings are held in c0- operative relationship with yielding pressure by suitable means such as the coiled springs 31 interposed between the driving ring and a part of the recess formed-in the interior of the casing 12 to receive said rings.

By preference and as herein shown a locking ratchet ring 32 is employed the same being located within and concentric of the driving ring 26 as clearly indicated in Figs. 3 and 4. This locking rlng has on its outer edge ratchetl teeth which engage with the ratchet teeth on the driven ring 25. The locking ring is a stationary one and in order to hold it thus it is provided at opposite sides with lugs 32a` which engage in sockets 33 in thejinterior of the casing 12. This ratchet ring while stationary as concerns rotation has a slight movement llongitudinally of the tool being held in yielding engagement with the driven ring in suitable manner as by means of the coiled springs 34 interposed between it and the body of the casing 12.

As hereinbefore stated the casing which contains the rotation mechanism is clamped between the main cylinder and the front head of the tool by means of the side bolts 9. In practice andl as shown in Fig. 4 the front end of the cylinder is vreduced in diameter and extends entirely through the casing 12, the reduction in diameter of the cylinder producing a shoulder 35 against which the rear end of such casing abuts. This reduced front end of the cylinder contains a bushing 36 within which the front r striking end ofthe piston 3 reciprocates and which also holds the striking piece or anvil 4. The rear end o1 the drill chuck is ot enlarged diameter so as to fit the exterior of@ the reduced end ot the m'ain cylinder, such chuck being mounted to rotate between such cylinder end and the rear end of the front head G. This head is arranged to interlock with the casing 12 for which purpose such casing is provided with a. flange 37 fitting into a corresponding counter bore in the rear end of the front head.

Describing a complete cycle of operation of the tool and starting with the parts in the position shown in Fig. 1, the motive fluid is delivered through the connection 10, port 2() and passages 21 and 22 to the front end of the main piston chamber, causing the piston 3 to be driven rearwardly. 1V hen the piston is in the position shownin Fig. 1 the rear end of the piston chamber is at exhaust through the rear exhaust groove 38 and exhaust port 39 which communicates with the atmosphere through an exhaust 'shut-off valve hereinafter described. The

piston in its rearward movement uncovers the front exhaust vgroove 38 exhausting the front-end of the piston chamber and the live motive fluid in the rear corners of the valve chamber acts upon the ball-valve forcing the latter to its right-hand position. At this time the front end of the piston chamber is at exhaust through the front exhaust groove 38 and exhaust port 39 and the live motive fluid is admitted through the supply connection l0 and ports 23 and 24 to the rear end of the-piston chamber so as to drive the piston to the position shown in Fig. 1. At this time, that is with the live motive fluid in the rear end of the piston chamber, a portion of such `fluid will pass through the ports 18 to the one end of the rotation cylinder 13 and 'other end of the rotation cylinder 14, thereby `driving their respective pistonsto the opposite ends of said rotation cylinders or chambers and locking the driving ratchet ring in the manner hereinbefore explained. At such time the opposite ends of these rotation cylinders are open to exhaust throughthe ports and passages 19 and the front exhaust groove 38 and front exhaust portV 39. The piston 3 in its forward reciprocation delivers its blow upon the anvil 4-which in turn delivers the blow upon the inner end of the drill bit 5. When the piston 3 in its forward movement has uncovered the 'rear exhaust groove 38, the motive fluid at that end ofthe piston chamber' will be exhausted and simultaneously live motive fluid in the frontend of the valve chamber exerting its force through the passages 21 and 22v will act upon the' ball-valve and drive it to its left-hand position. At this time the live motive Huid will pass throughv the ports and passages 19 to their end of the rotation cylinders or piston chambers so as to ,drive or rock the driving ring in the other direction. The ball-valve is arranged in av cage 1la which has openings 11b for the passage of the live motive Huid. It will be understood that these openings are somewhat restricted as compared with the passages leading from the valve cage to the opposite ends of the main piston chamber with the result that the described valve operations can take place.

As hereinbefore stated the two exhaust grooves 38 communicate with similar eX- haust ports 39. These exhaust ports in turn communicate through corresponding-.registering `ports of a shell valve 40 with the interior thereof, such valve being open at one end to the atmosphere. This valve4 is arranged to oscillate in a chamber 41,ex tending longitudinally of the piston chamber 2, such valve acting asan exhaust shutofl".v This valve is adapted to be manually manipulated by meansv of a handle 42 secured to the solid end of the valve and arranged to move through the slot 43 in the outer wall of the chamber 41.. This slot is provided along one4 edge withl a series of notches 43a into which the handle is springpressed and thereby held in different adjusted positions. As shown a lspring 44 is interposed between a pin or stud 45 rotatably connected with the solid end of the valve and the plug 46 at the outer end of the chamber 41. According to this construction th-e valve 40 may be oscillated by means of the handle 42 so as to bring the exhaust ports 39l out of register with the ports in the valve,lthereby shutting 0H the exhaust. When the handle 42 is released the spring 44 will move the valve 40 slightly longitudinally into engagement with one of the notches 43a'. In restoring the valve 40 to open exhaust position the reverse operationl takes place, that is the valve 40 is moved Slightly rearwardly to bring its handle out of the notch 43 and is then swung to open position. When this position is reached and the operators hold on the handle 42 is released the spring 44 will force such handle to one of the other notches-43a thereby retaining such valve in its open exhaust position.

The exhaust shut-off valve 40 is provided for the purpose of enabling the motive fluid to be discharged through the drill bit and to thereby blow out the cuttings in the and 5al to the cutting end of the drill bit or steel. It will belunderstoodthat the passage 4a isof limited carryingcapacity in order not to interfere with the reciprocations of the piston 3. Every time the motive fluid is admitted tothe front end of the main piston 'chamber a portion thereof thus passes down 'through the anvil and .through the hollow steel for the purpose stated.

In the event that the supply of air delivered to thecutting end of the drill bit is insuiiicient so that the hole 'is not being properly cleared lof chips or cuttings, the exhaust valve 40 is closed. The piston 3 will travel rearwardly but upon reaching its rearward and through thevdrill bit to eject the chips or cuttings. By these means the piston 3 is rendered inoperative and adirect and continuous supply of air is delivered through the' tool to the cutting end of the drill bit.

means for rotating the chuck including a' driven ratchet ring removably secured to the inner end of the chuck and having a bearing ange, a driving ratchet ring coperating with the driven ring, a casing containing said rings and providing a bearing for the flange ofthe first-named ring, and fluid pressure mechanism for oscillating the driving ring.

2. The combination of a reciprocating type of drilling engine operated by motive iuid and having a rotatable drill chuck, and means for rotating the chuck comprising a driven ratchet ring removably secured to t-he inner end of the chuck and having a bearing flange, a driving ratchet ring coperating With the driven ring, a casing containing said rings and providing a bearing for the flange of the' first-named ring, a stationary locking ring coperating With the driven ring, and liuid pressure mechanism. ,for oscillatingthe driving ring.

3. The combination `of a reciprocating type of drilling engine operated by motive fluid including the cylinder and a rotatable drill chuck at the front end thereof, and means for rotating the chuck comprising a driven ratchet ring detachably connected With the inner end of the chuck and arranged in a plane at right angles to the axis of rotation of the chuck, a driving ratchet ring cope'ratingj With the driven ring, a stationary locking ring coperating With the driven ring and arranged concentric thereof, a casing 12 arranged at the front end'of the cylinder and having annular cavities to receive said rings, springs 31 and 34e in said cavities behind the driving and locking rings for pressing them into engagement With the driven ring, and Huid pressure mechanism independent of the drill-actuating piston for oscillating the driving ring.

4. The combination With a drilling engine including its cylinder and front head, said cylinder having a reduced front end, of a drill chuck mounted to rotate in the head and having an inner bearing upon such reduced end of thecylinder, a casing fitting upon said reduced end and interposed between the main body of the cylinder and the front head, and fluid pressure operated mechanism contained Within the casing for rotating the chuck.

5. The combination with a drilling en'- gine including its cylinder and front head, said cylinder having a reduced front end, of a drill chuck mounted to rotate in the head and having aninner bearing upon such reduced end of the cylinder, a casing fitting upon said reduced end and interposed between the main body of the cylinder and the front head, and fluid pressure operated mechanism contained Within the casing for rotating the chuck, said casing being formed in two detachable sections.

6. The combination With a drilling engine including its cylinderv and front head, of a drill chuck mounted to rotate in the head, a casing interposed between thehead and cylinder, the cylinder having an extension projectingthrough the casing, a driven ratchet ring detachably connected to thechuck, a driving ratchet ring arranged to coperate With thedriven ring, and a locking'ring cooperating With the driven ring, said driven ring and locking ring being mounted Within the casing and directly on the cylinder extension, and the driving ring being mounted on the locking ring.

MATHER W. sHERWooD. l

Witnesses: l l

PAUL G. HEATH, J. B. VILLIAMS. 

